1. Field of the Invention
This invention generally relates to improving washer performance for machined and all other types of parts that require washing. More particularly, the present invention relates to a washer bath including a filtration system for removing emulsified oil and oil attracted to the soap, dirt and free oil.
2. Description of Related Art
During a typical lathe or other machining operation, metal chips of varying size and shape are formed. After a machining operation, the machined part needs to be cleaned. The cleanliness of the machined part is generally determined by all of the debris and/or oil remaining that is not removed or dissolved by the cleaning solutions.
Industrial washer baths are used to remove the debris such as metal chips as well as swarf (generally smaller particles than the chips), oil, chemical compounds, dirt and the like. Industrial baths are known to include centrifuges or ultra filters. That is, related art washer technology requires using the centrifuge and ultra filter units separately on a washer clean tank. The washer bath life extension process in the related art has not been successful in using an ultra filter or centrifuge separately to extend the washer bath life.
The chips that remain after the machining operation of the part that have not yet been removed from the part, have oil on them and the oil is attracted to the metal of the part and the metal of the chip. The force produced by the weight of the chip is less than the force created by the oil's attraction to the part and chip. The current soap technology uses surfactant or OH— to get between the oil and the part to break the surface tension of the oil/part boundary. When swarf dirt passes thru the filter devices of the related art, the dirt will come into contact with the oil on the part and the swarf is attracted to the oil.
Typically, a water based coolant is used in the process of machining the part and an emulsifier is used the hold to oil molecules to the water molecules. When the coolant is removed from the part in the washer, the this oil will go into solution. However, in the washer bath, this oil will attract swarf in the fluid. As a result, the oil and swarf can be passed through the filter and the dirt can be deposited back onto the part reducing the effectiveness of the cleaning operation.
During use, an ultra filter has the fluid pumped through the inside of the membrane filter. The good soap passes from inside to outside of the membrane and the bad soap, the oil, and swarf stays on the inside of the membrane. The fluid pumped through the inside of the membrane is returned to a tank called a concentrate tank. As the bad soap, oil and swarf percent increases in the concentrate tank, the filter effectiveness decreases. Since the tank has no method of removing swarf and free oil, the fluid flow of the good soap will be stopped and the tank must be dumped. However, the turning on and off of the fluid flow to the ultra filter membranes causes pressure shock to the membrane, which will lower the life of the membrane. Even further, the return from the membrane is above the input to the pump which supplies the membrane. As such, the oil and swarf are kept mixed in the solution. Accordingly, the ultra filters used in the related art require high maintenance, such as cleaning the filter membrane frequently.
In washer baths, the efficacy of the soap used to clean the parts should be tested to determine if the soap can continue to clean the parts. As discussed above, the soap includes chemicals that are attracted to the oil and also includes a surfactant that helps to break the oil and dirt surface tension. If the bath has more oil than chemicals that are attached to the oil, then the soap is used up. The related art does not provide a clean and efficient process to measure this condition or to measure the amount of soap available to clean. The related art soap testing method requires a measurement of the parts to determine when the soap can no longer clean the parts. Further, there is no way to measure the chemicals in the soap to determine if harmful chemicals are being built-up in the bath. Again, the parts must be measured, which is a time consuming process. Accordingly, the related art does not provide a method to measure soap effectiveness.